Artificial tooth



@cic. '10, i933. v H SEARS 1,930,065

ARTIFICIAL TOOTH Filed June 10. 1931 Patented Oct. 10, 1933 UNITED STATES PATENT OFFICE 2 Claims.

This invention relates particularly to artificial teeth for bridge-work although the invention is equally susceptible to use in other artificial dentures, such as plates.

One object of the invention is to provide a novel and improved construction and combination of a tooth facing and a metal backing for securing the tooth facing in position on a bridge or dental plate, whereby the tooth facing can be easily and quickly applied to the backing with a rotative sliding movement and so that the tooth shall be securely interlocked with the backing, both on the lingual side of the tooth as Well as on the side proximal surfaces thereof.

Another object is to provide a novel and improved combination of a tooth facing and a metal backing wherein the tooth and backing have interlocking arcuate ribs or projections and grooves or recesses so that the tooth may be secured on the tooth backing by a rotative sliding action of said ribs into said grooves.

A further object is to provide an artificial tooth of the character described wherein the tooth facing shall be positively interlocked with the tooth backing on the lingual side of the tooth, and wherein the metal backing terminates short of both the gingival and occlusal ends of the tooth facing, so that the translucency of the facing at the occlusal end of the tooth is unimpaired and contact of the metal backing with the gum is prevented.

Other objects are to provide an artificial tooth of this character which shall be simple and inexpensive in construction and easy to mount; to 35 provide such an artificial tooth wherein the strains are effectually distributed to provide proper reinforcement of the tooth face by the backing; and to obtain other advantages and results as will be brought out by the following description.

40 Referring to the accompanying drawing in which corresponding and like parts are designated throughout the several views by the same reference characters,

Figure 1 is a side elevation of an artificial tooth showing the tooth facing and the backing in as sembled relation.

Figure 2 is a transverse vertical sectional view on the line 2-2 of Figure 6 showing the tooth facing and the backing in assembled relation by 50 solid lines, and illustrating the manner of assembling the parts by dot and dash lines.

Figure 3 is a similar View on the line 33 of Figure 6.

Figure 4 is a front elevation of the backing shown in Figures 1 to 3 inclusive.

Figure 5 is a perspective view showing the lingual side of the tooth facing illustrated in Figures 2 and 3.

Figure 6 is a transverse sectional view on the line 6-6 of Figure 3.

Figure 7 is a fragmentary vertical sectional view on the line 77 of Figure 3.

Figure 8 is a side elevation showing a modification of the construction illustrated in Figure 1.

Figure 9 is a view similar to Figure '7 showing a modification of the construction shown in Figure 7.

Specifically describing the invention, the reference character G designates a tooth facing for an anterior or incisor tooth and H represents the metal backing which is secured to the lingual side of the facing between the gingival end 1 and the occlusal end 2. The facing G has two surfaces 15 and 16 on the lingual side thereof disposed at an obtuse angle to each other. In one of these surfaces adjacent the occlusal end of the facing are formed undercut recesses 17 to receive correspondingly shaped lugs 13 projecting from a surface 19 of the backing H corresponding to the surface 15 of the facing. The so backing H has another surface 20 corresponding to the surface 16 of the facing, and from this surface 20 projects a boss 21 to fit a correspondingly shaped recess 22 in the surface 16 of the facing. The fioor wall of the recess 22 is preferably arcuate with the bases or bottom sides of the recesses 17 in the facing as a center and the top 23 of the boss 21 is correspondingly shaped.

The facing is applied to the backing by first inserting the lugs 13 into the recesses 17, after which the facing is swung with a rotative motion about the lugs 18 as shown by dot and dash lines in Figure 3, until the boss 21 enters the recess 22 and the surface 16 of the facing abuts the surface 20 of the backing, as shown by solid lines in Figure 3. Cement is applied to the contacting surfaces of the facing and the backing.

A modification of this form of the invention is illustrated in Figure 8 where the backing has flanges 24 at its sides to enter depressions 25 in the side surfaces of the facing. These flanges 24 add to the strength of the interlocking connection of the facing and the backing, and with the lugs 18 and boss 21 eifectually prevent relative sliding movement of the facing and back- 105 ing in all directions including side-wise movement.

The boss 21 may be made of any transverse sectional shape, either with straight sides as shown in Figure 7 or with undercut sides as 110 shown in Figure 9, and these sides are preferably diagonal to the front of the boss as shown.

With such a construction, it will be observed that the facing and backing may be easily and quickly assembled; that the facing and backing will be securely interlocked both on the lingual surface and the side or proximal surfaces of the facing; and that the backing will terminate short of both the gingival and the occlusal ends of the facing so as to in no way impair the translucency of the facing at the occlusal end, and so as to insure that the backing shall not contact with the gum.

While I have shown and described my invention as embodied in certain details of construction, it should be understood that this is primarily for the purpose of illustrating the principles of the invention and that many modifications and changes may be made in the details of construction without departing from the spirit or scope of the invention.

Having thus described my invention what I claim is:

I. An artificial tooth comprising a facing and a backing, said facing having on its lingual side two surfaces at an obtuse angle to each other and said backing having corresponding surfaces, said facing having a recess in one surface adjacent the'occlusal end thereof with the wall nearest said occlusal end undercut, and having a second recess in the other surface, said backing having a lug to enter the first recess and a boss to enter the second recess, said second recess having its floor wall arcuately curved with said undercut Wall of said first recess as a center, and said boss having its top wall curved correspondingly to said floor wall, whereby said facing and said backing can be connected by inserting said lug in said first recess and relatively rotating said facing and backing about said lug and said undercut Wall of the first recess.

2. An artificial tooth comprising a facing and a backing, said facing having on its lingual side two surfaces at an obtuse angle to each other and said backing having corresponding surfaces, said facing having a recess in one surface adjacent the occlusal end thereof with the wall nearest said occlusal end undercut and having a second recess in the other surface, said backing having a lug to enter the first recess and a boss to enter the second recess, said second recess being dovetail shaped in transverse section and having its floor wall arcuately curvedwith said undercut wall of said first recess as a center, and said boss being correspondingly dovetail shaped in transverse section and having its top wall curved correspondingly to said floor wall of the second recess, so that said facing and said backing can be connected by inserting thesaid lug into said first recess andrelatively rotating saidv facing and backing about said lug and said undercut wall of the first recess to move said boss on the backing into said second recess.

VICTOR H, SEARS. 

